Tool and die



Pal;e nted Aug. 25, 192 5.

KARL scnno'rnn, or" LICHTENIBEBG, I Am) HELM muss-nu, or seriousness, Gna- MANY, nssre'uons 'ro GENERA ntnorarofcomrmr, AIconronArroN on NEW YORK.

No Drawing.

To all whom it may concern: 7 Be it known that we, KARL SoHRo'rER and WILHEL JENSSEN, citizens of the German Republic, residing, respectively, at Lichten-- berg, Germany, and Schoneberg, Germany, have invented certain, new and useful Improvements in Tools and Dies, of which thefollowing is a specification.

Our invention relates to hard tools, dies, 10 molds, drawing blocks and other imple-v ments. Heretofore devices of this type have been made from carbides of'metals which I fuse at high temperatures. Such devices are not satisfactory for use in connection with the working of metals such. as tungsten because'such devices are too brittleand are also toocoarse and they break easily. Our invention relates to the method of making such devices which are free'from the above objections. For the purpose of makingsuch tools or devices, we make use of metals that fuse at a temperature of over flOOO deg. C. and which are found in the fourth, fifth and sixth groups of the periodic system. We also may use their mixtures or alloys. Tools made from these metals we treat with carbon, boron orother metalloids in such a manner that their working surfaces are rendered hard by such'material. This can be done by heatingthe metal in an atmosphere of these substances and at a temperature below the fusing point of the metal, mixture or alloy. The process ofour invention is hereinafter more fully set forth and claimed.

Among the specific elements which may be used .and treated in accordance with our process are the following: titanium, zir-t conium, thorium, silicon, vanadium, tantalum, chromium, molybdenum, tungsten, uranium. We may also use alloys of these metals or their mixtures. Such a metal can be brought to the desired form by taking the powder of the element, as'in the case of tungsten, and molding it into the desired 1 shape 1n a hydraulic press, after whichit isheated in a neutral or reducing atmosphere to sinter. It is also possible to forge or cast the metal alloy or mixture in which case .sintering is not necessary.

.After the metal has been formed into the desired shape, it is subjected to a carboniz.-'

ing, boronizing or av similar process at a moor. Ann DIE. I

Application filed December 27, 1922. Serial 1T0. 609,836.'-. I

.temperature below the fusing point'of'the metal. For this purpose the tool orimplement..is heated in an atmosphere containing either" carbon, boron or. the like, such for. example, as-hydrocarbons, boron hydride, carbon; oxide, etc. or, s uitablemix tures of the same. As an alternative, the

implement may be covered with carbon,

boron, or carbon 'or boron containing sub-- stances which at the temperature employed read ly-giveoif carbon or boron tothe implement.- The process may-also be carried out in. a carbonizing or boronizing gaseous atmosphere until the gas is reduced to a neutral-condition- It'is also possible to start the process with one gas and complete the process with a different gas and the sequence as well as the mixture can be varied to obtain any desired result, as for example, to

produce an outer coating of suitable hardness on top of substrata of diminishing degrees of hardness. The separate layers or zones do not change sharply in hardness;

one layer gradually merges into another so that the-outer layer is richest in carbon, gradually diminishing toward the interior. The same is the case with respect to boron and the like. In certain cases after the implement has been treated and subjected to 2 accordance with this process can be used also for face'plates, crucibles and also for armature andstove parts. I

It will be seen, therefore, that tools and implements made in accordance with our process have several zones which vary in hardness as the layer approaches the sur face, the hardest layer being found on top.

What we claim as new and desire to secure by Letters Patent of the United States,

.1s 1. An implement having as a foundation one of; the elements of the fourth, fifth and sixth groups of the periodic system fusible ioo at over 1000 C. and provided with a sur face having in combination such element and a. metalloid.

2. An implementha-vingas a foundation one of the elements of the fourth, fifth and sixth groups of the periodic system fusible at over 100Q C. and provided with a surface consisting of layers of different pro-.

portions of the metal and a. metalloid.

3. An implement having as a'foundation tungsten and provided with a surface having in combination metalloid.

4. An implement having as a, foundation tungsten and provided with a. surface con- 15 sisting of layers of different proportions of the metal and a metalloid.

Inwitness whereof, we have hereunto set our hands this 4th day of December, 1922.

KARL SCI-IRO'TER. WILHELM JENSSEN.

such element and. a 

